/**
* Prepares the relationships specified using with().
*
* @return array Relationship definitions used by \PHPixie\ORM\Result
* @throw \Exception If the relationship specified using with() does not exist or is not of the belongs_to or has_one type
*/
public function prepare_relations()
{
$paths = array();
if (!empty($this->_with)) {
$fields = array();
$this_alias = $this->query->last_alias();
foreach ($this->columns() as $column) {
$fields[] = array("{$this_alias}.{$column}", "{$this_alias}__{$column}");
}
foreach ($this->_with as $target) {
$model = $this;
$model_alias = $this_alias;
$rels = explode('.', $target);
foreach ($rels as $key => $rel_name) {
$path = implode('.', array_slice($rels, 0, $key + 1));
if (isset($paths[$path])) {
$model = $paths[$path]['model'];
$model_alias = $paths[$path]['alias'];
continue;
}
$alias = $this->query->add_alias();
$model_rels = array_merge($model->has_one, $model->has_many, $model->belongs_to);
$rel = $this->pixie->arr($model_rels, $rel_name, false);
if (!$rel) {
throw new \Exception("Model '{$model->model_name}' doesn't have a '{$rel_name}' relation defined");
}
if ($rel['type'] == 'has_many') {
throw new \Exception("Relationship '{$rel_name}' is of has_many type and cannot be preloaded view with()");
}
$rel_model = $this->pixie->orm->get($rel['model']);
if ($rel['type'] == 'belongs_to') {
$this->query->join(array($rel_model->table, $alias), array($model_alias . '.' . $rel['key'], $alias . '.' . $rel_model->id_field), 'left');
} else {
$this->query->join(array($rel_model->table, $alias), array($model_alias . '.' . $model->id_field, $alias . '.' . $rel['key']), 'left');
}
foreach ($rel_model->columns() as $column) {
$fields[] = array("{$alias}.{$column}", "{$alias}__{$column}");
}
$model = $rel_model;
$model_alias = $alias;
$paths[$path] = array('alias' => $alias, 'model' => $model);
}
}
call_user_func_array(array($this->query, 'fields'), $fields);
}
return $paths;
}
